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Ultraviolet patterns of flowers revealed in polymer replica – caused by surface architecture
摘要： Angiosperms and their pollinators are adapted in a close co-evolution. For both the plants and pollinators, the functioning of the visual signaling system is highly relevant for survival. As the frequency range of visual perception in many insects extends into the ultraviolet (UV) region, UV-patterns of plants play an important role in the flower–pollinator interaction. It is well known that many flowers contain UV-absorbing pigments in their petal cells, which are localized in vacuoles. However, the contribution of the petal surface microarchitecture to UV-reflection remains uncertain. The correlation between the surface structure and its reflective properties is also relevant for biomimetic applications, for example, in the field of photovoltaics. Based on previous work, we selected three model species with distinct UV-patterns to explore the possible contribution of the surface architecture to the UV-signaling. Using a replication technique, we transferred the petal surface structure onto a transparent polymer. Upon illumination with UV-light, we observed structural-based patterns in the replicas that were surprisingly comparable to those of the original petals. For the first time, this experiment has shown that the parameters of the surface structure lead to an enhancement in the amount of absorbed UV-radiation. Spectrophotometric measurements revealed up to 50% less reflection in the UV-absorbing regions than in the UV-reflecting areas. A comparative characterization of the micromorphology of the UV-reflecting and UV-absorbing areas showed that, in principle, a hierarchical surface structure results in more absorption. Therefore, the results of our experiments demonstrate the structural-based amplification of UV-reflection and provide a starting point for the design of bioinspired antireflective and respectively strongly absorbing surfaces.
关键词： hierarchical structures,biomimetics,light absorption,light harvesting,light reflection
更新于2025-10-22 19:40:53
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A Lesson from Nature: Biomimetic Self-assembling Phthalocyanines for High-efficient Photothermal Therapy within the Biological Transparent Window
摘要： Development of facile but high-efficient small organic molecule based photothermal therapy (PTT) in the in vivo transparent window (800-900 nm) has been regarded as a minimally invasive and most promising strategy for potential clinical cancer treatment. Phthalocyanine (Pc) molecules with remarkable photophysical and photochemical properties as well as high extinction coefficients in the near-infrared region are highly desirable for PTT, but as far satisfying single-component Pc-based PTT within the in vivo transparent window (800-900 nm) has very rarely been reported. Herein, inspired by the self-assembly algorithm of natural bacteriochlorophylls (BChl's) c, d, and e, biomimetic self-assembling tetrahexanoyl Pc Bio-ZnPc with outstanding light-harvesting capacity was demonstrated to exhibit excellent PTT efficacy evidenced by both in vitro and in vivo results, within the biological transparent window.
关键词： photothermal therapy,phthalocyanine,biological transparent window,self-assembly,biomimetics
更新于2025-09-23 15:23:52
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Biomimetic fog harvesting surface by photo-induced micro-patterning of zinc-oxide silver hierarchical nanostructures
摘要： As water scarcity has become a major global problem, fog-harvesting technologies are considered an effective sustainable solution for water resources. Here, we report a novel approach to the fog-harvesting technology using zinc oxide-silver hierarchical nanostructures to mimic the Stenocara beetle’s back. Vertically aligned zinc oxide nanowires are first fabricated by a cost-effective and scalable hydrothermal method to produce a super-hydrophilic surface. Silver nanoparticles are then selectively synthesized by an additional photo-induced synthetic process on the zinc oxide nanowire surfaces to form a hydrophobic surface using the hierarchical nanostructures. The fog-harvesting performance was investigated using an artificial fog flow and by measuring the amount of harvested water for efficient fog harvesting. On the superhydrophilic surface, although the water droplets immediately were captured, they formed a puddle at the bottom of the surface due to the high adhesion between water and the surface. In contrast, on the hydrophobic surface, the capturing rate was very low even though the water droplets easily rolled off the surface. Compared to the non-patterned surface, the captured water film on the patterned hydrophilic region grew rapidly into a spherical shape and separated from the surface due to the surrounding hydrophobic regions. As a result, the patterned surface with 0.5 mm pattern size afforded a higher fog collection rate of 1233 mg/h than those of the superhydrophilic and hydrophobic surfaces of 1105 mg/h and 879 mg/h respectively.
关键词： Fog harvesting,Biomimetics,Hierarchical nanostructure,Surface wettability
更新于2025-09-23 15:22:29
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Optical Shielding of Ultracold <sup>39</sup> K-Cs Collision
摘要： To touch and be touched are vital to human development, well-being, and relationships. However, to those who have lost their arms and hands due to accident or war, touching becomes a serious concern that often leads to psychosocial issues and social stigma. In this paper, we demonstrate that the touch from a warm and soft rubber hand can be perceived by another person as if the touch were coming from a human hand. We describe a three-step process toward this goal. First, we made participants select artificial skin samples according to their preferred warmth and softness characteristics. At room temperature, the preferred warmth was found to be 28.4 C at the skin surface of a soft silicone rubber material that has a Shore durometer value of 30 at the OO scale. Second, we developed a process to create a rubber hand replica of a human hand. To compare the skin softness of a human hand and artificial hands, a robotic indenter was employed to produce a softness map by recording the displacement data when constant indentation force of 1 N was applied to 780 data points on the palmar side of the hand. Results showed that an artificial hand with skeletal structure is as soft as a human hand. Lastly, the participants' arms were touched with human and artificial hands, but they were prevented from seeing the hand that touched them. Receiver operating characteristic curve analysis suggests that a warm and soft artificial hand can create an illusion that the touch is from a human hand. These findings open the possibilities for prosthetic and robotic hands that are life-like and are more socially acceptable.
关键词： rubber hand illusion,biomimetics,Artificial skin,prosthetics
更新于2025-09-19 17:13:59
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[IEEE 2019 5th International Conference on Advances in Electrical Engineering (ICAEE) - Dhaka, Bangladesh (2019.9.26-2019.9.28)] 2019 5th International Conference on Advances in Electrical Engineering (ICAEE) - Simulation and Modeling of Graded Band-Gap Perovskite Solar Cells
摘要： Conventional musculoskeletal models mainly consist of bones modeled by rigid linkages, and muscles, tendons, and ligaments modeled by ideal wires. The lack of volumetric modeling of muscle makes a representation of interaction between muscles and natural muscle pathway difficult. This difficulty results in a physiologically inappropriate estimation of a muscle momentum arm that is critical for a muscle activity estimation. In this letter, we develop a volumetric skin-musculoskeletal model based on an anatomographic human shape database to improve an estimation of a muscle momentum arm. A volumetric deformation of surface skin and muscle is realized by an extended skeleton subspace deformation (SSD, the linear blend skinning algorithm) that considers a surface profile of bone with low computational cost. This extended SSD considers a sub-bone that is projected to the bone surface polygon so that the skin and muscle deformation is significantly affected by the bone surface profile. The surface-based SSD realized the natural skin deformation avoiding a penetration between skin and bones during trunk rotation that results in a physiologically appropriate estimation of a muscle momentum arm. The volumetric skin-musculoskeletal model and the surface-based SSD estimates the momentum arm of vastus lateralis with 14.1% maximum error from a literature values, though there is 44.8% maximum error with the wire musculoskeletal model. This model would accurize a muscle activity estimation that leads to a more correct understanding of human motion control/generation mechanisms.
关键词： Simulation and Animation,biomimetics
更新于2025-09-19 17:13:59
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ZnO nanocrystals shuttled by extracellular vesicles as effective Trojan nano-horses against cancer cells
摘要： The effective application of nanoparticles in cancer theranostics is jeopardized by their aggregation in biological media, rapid degradation and clearance. The design of biomimetic nanoconstructs with enhanced colloidal stability and non-immunogenicity is therefore essential. We propose naturally stable cell-derived extracellular vesicles to encapsulate zinc oxide (ZnO) nanocrystals as efficacious nanodrugs, to obtain highly biomimetic and stable Trojan nano-horses (TNHs). Materials & methods: Coupling efficiency, biostability, cellular cytotoxicity and internalization were tested. Results: In vitro studies showed a high internalization of TNHs into cancer cells and efficient cytotoxic activity thanks to ZnO intracellular release. Conclusion: TNHs represent an efficient biomimetic platform for future nanotheranostic applications, with biomimetic extracellular vesicle-lipid envelope, facilitated ZnO cellular uptake and potential therapeutic implications.
关键词： biomimetics,extracellular vesicles,colloidal stability,cytotoxicity,nanocrystals,zinc oxide
更新于2025-09-11 14:15:04